1. Field of the Invention
The present invention relates to the reprocessing of animal bedding material; and more particularly to a system and process for cleaning and sanitizing animal bedding material to remove animal waste products commingled therein, permitting it to be reused as bedding or recycled as a raw material for producing other end-use products.
2. Description of Related Art
Domestic animals are widely kept by humans for pleasure, sport, or doing useful work. These animals are often housed in stalls, pens, cages, or other confining enclosures in which a bedding material is disposed on the floor to absorb the liquid and solid waste products of the animal. The absorbency of the bedding material reduces the animal's contact with the waste, improving comfort and minimizing skin irritation and disease. Large animals, such as horses, produce proportionately large amounts of waste. For example, it is estimated that a typical horse weighing about 1000 pounds may produce as much as about 30 pounds of feces and 2.5 gallons of urine daily, for a total of some 50 pounds of total raw waste per day. Soiled bedding removed with the manure during stall cleaning may account for another 8 to 15 pounds per day of waste, resulting in about 12 tons of waste a year per horse. Disposal of this matter presents serious aesthetic issues and, more importantly, environmental concerns for air and water pollution if the waste enters surface bodies of water or underground aquifers. The concerns are particularly acute for farms or other facilities that house large numbers of horses or other large animals.
Conventional practice is that animal bedding is used once and then discarded. Costs, both for producing new bedding and for disposing it after use, continue to increase. Most commonly, the materials used for animal bedding are plant-based. For livestock such as cattle and poultry, straw, hay, sawdust, kenaf, or wood shavings, or combinations thereof, are typically used. Equine bedding typically includes pressed wood pellets, wood shavings, kenaf, or sawdust. With the decline in construction and in manufacture of wood based products there has been a significant decline in the availability of wood pellets, shavings, and sawdust. As a result, bedding can be difficult to find and the cost has increased. Although certain synthetic, polymeric materials have been proposed for bedding, they have not received widespread acceptance in the agricultural community.
Along with the supply problems, costs for disposal have also increased and available techniques are constrained by environmental concerns and, in some cases, by governmental regulations.
Current methods of disposal include: i) composting, ii) spreading on land as fertilizer, iii) stockpiling near the point of generation, and iv) landfilling. Although some benefits may be derived, each of these solutions entails significant difficulties and objections. Composted manure can be used as potting soil, but the process requires a significant amount of land that is sufficiently isolated to prevent the inevitable odors from adversely impacting neighboring properties. Spreading the soiled bedding on land disperses both the waste material and the sawdust, shavings, or the like that form the base of the bedding. While the waste gradually decomposes to provide nutrients compatible with some crops, the concomitant bedding material causes dilution of the soil. As a result, dispersing the material is now being scrutinized and may ultimately be banned. Stockpiling poses a substantial risk that undesired substances may be leached into either underground aquifers or surface bodies of water. In addition, odors emanating a waste pile are objectionable. Landfill dumping incurs substantial and increasing costs for transportation and land fill operation. Moreover, many landfills do not accept manure, as it can interfere with the normal anaerobic decomposition processes if applied improperly or in excessive quantities. Governmental agencies are becoming increasingly concerned about waste management, and therefore have provided some funding through grants and low interest loans for landfill diversion.
The few processes heretofore proposed for separating animal manure and recycling used bedding are typically expensive and detrimentally alter the physical structure and appearance of the material. Thus, they have not been found satisfactory and readily accepted in the marketplace.